There seems to be a bug since change 3ca54d4d1c73: The download link generated by the extension still has as action 'download-electron-pdf' which is no longer recognized, hence the choice screen is shown.
This should fix it:
--- a/src/ElectronPdfServiceHooks.php
+++ b/src/ElectronPdfServiceHooks.php
@@ -90,7 +90,7 @@ class ElectronPdfServiceHooks {
return $specialPageTitle->getLocalURL(
[
'page' => $title->getPrefixedText(),
- 'action' => 'download-electron-pdf'
+ 'action' => 'redirect-to-electron'
]
);
}